[Cytotoxic alkaloids from stems of Nelumbo nucifera]

Chemical investigation was carried out to study the alkaloids from stems of Nelumbo nucifera and their cytotoxic activities. The constituents were separated by column chromatography, and their structures were elucidated by spectroscopic data analyses. The isolated compounds were evaluated for their cytotoxic activities by MTr method. Fifteen compounds were isolated from the total alkaloids extract and identified as asimilobine (1), isococlaurine (2), N-acetylnorarmepavine (3), crykonisine (4), velucryptine (5), pycnarrhine (6), liriodenine (7), nuciferine (8), nornuciferine (9), armepavine (10), N-methylasimilobine (11), coclaurine (12), N-norarmepavine (13), N-methylcoclaurine (14) and lysicamine (15). Compounds 1-7 and 12-15 were isolated from stems of this plant for the first time, and compounds 2-6 were firstly isolated from the family Nelumbonaceae. Compounds 7-10, 13 and 14 showed significant cytotoxic activities against HL-60 carcinoma cell line with inhibitory ratios of 51.36%, 59.09%, 52.51%, 53.93%, 51.43%, and 64.31% at concentration of 1 x 10(-5) mol x L(-1), respectively.

Inhibition of pancreatic lipase, α-glucosidase, α-amylase, and hypolipidemic effects of the total flavonoids from Nelumbo nucifera leaves

ETHNOPHARMACOLOGICAL RELEVANCE

Nelumbo nucifera Gaertn. leaves have been used as medicinal herbs in the past 1300 years, specifically utilized to cure hyperlipidemia, hyperglycemia, and obesity. It has been recorded in the most famous medicinal book in China for more than 400 years. The present study aims to identify the potential therapeutic activities of the flavonoids isolated from Nelumbo nucifera leaves.

MATERIALS AND METHODS

Nelumbo nucifera leaf flavonoids (NLF) were tested for the inhibition of lipase, α-glucosidase, and α-amylase activities in vitro. A single dose of NLF was administered by oral gavage in mice for acute toxicity. Wistar rats with high-fat diet-induced hyperlipidemia and two other animal models were used to evaluate the hypolipidemic effects of NLF.

RESULTS

Our in vitro biochemistry tests revealed that the NLF showed high inhibitory activity against porcine pancreatic lipase, α-amylase, and α-glucosidase with IC50 values of 0.38 ± 0.022, 2.20 ± 0.18, and 1.86 ± 0.018 mg/mL, respectively. Furthermore, the NLF significantly lowered the lipid components, such as the total cholesterol, triglycerides, low-density lipoprotein cholesterol, and malondialdehyde, in various established in vivo systems and raised the high-density lipoprotein cholesterol. Moreover, the NLF alleviated high-fat diet-induced lipid accumulation in the liver.

CONCLUSIONS

The results demonstrate that NLFs can effectively ameliorate hyperlipidemia and inhibit the key enzymes related to type 2 diabetes mellitus. Our findings may provide new pharmacological basis for the treatment of hyperlipidemia, hyperglycemia, and obesity using NLFs.

Protective effects of alkaloid compounds from Nelumbinis Plumula on tert-butyl hydroperoxide-induced oxidative stress

This study was conducted to investigate the effect of Nelumbinis Plumula total alkaloid (NPA) and its main alkaloid components on oxidative stress induced by tert-butyl hydroperoxide (t-BHP) in the human hepatocellular HepG2 cell line. According to HPLC analysis, several major alkaloid compounds such as liensinine, isoliensinine and neferine were present in NPA. The cytotoxic effects in 0.55 mM t-BHP-induced HepG2 cells were significantly inhibited by NPA and the major compound in NPA, neferine, showed the strongest activities. The protective effect of neferine against oxidative stress induced by t-BHP may be associated with decreased ROS formation, TBARS generation, LDH release and increased GSH levels, suggesting their involvement of the cytoprotective on oxidative stress. The effects were comparable with quercetin, which was used as positive control. Overall, total alkaloid and alkaloid compounds from Nelumbinis Plumula displayed a significant cytoprotective effect against oxidative stress. Further study is needed to elucidate the relationship between the chemical structures of the components in NPA and their protective effect on oxidative stress.

Neferine isolated from Nelumbo nucifera enhances anti-cancer activities in Hep3B cells: molecular mechanisms of cell cycle arrest, ER stress induced apoptosis and anti-angiogenic response

Hepatocellular carcinoma (HCC) is one of the most aggressive malignant diseases and is highly resistant to conventional chemotherapy. Neferine, a major bisbenzylisoquinoline alkaloid derived from the embryos of Nelumbo nucifera, has been reported a few physiological activities. However, the mechanisms of anticancer effects are not well understood and its detailed activities on Hep3B cells have not been determined. Our results suggest that neferine exhibited cytotoxicity against HCC Hep3B cells, but not against HCC Sk-Hep1 and THLE-3, a normal human liver cell line. In addition, consistent with the induction of G1/S phase cell population in flow cytometry, downregulation of c-Myc, cyclin D1, D3, CDK4, E2F-1, as well as dephosphorlyation of cdc2 by western blot analysis, as evidenced by the appearance of cell cycle arrest, were observed in Hep3B cells treated with neferine. Our results demonstrated neferine induced ER stress and apoptosis, acting through multiple signaling cascades by the activation of Bim, Bid, Bax, Bak, Puma, caspases-3, -6, -7, -8 and PARP, and the protein expression levels of Bip, calnexin, PDI, calpain-2 and caspase-12 were also upregulated dramatically by neferine treatment. Overexpression of GFP-LC3B by neferine resulted in a diffuse cytosolic GFP fluorescence and the strong fluorescent spots, representing autophagosomes. The significant reduction of the migration in Hep3B cells and the capillary tube-like formation of HUVECs by neferine were also determined. These observations reveal that the therapeutic potential of neferine in treating HCC Hep3B cells, containing copies of hepatitis B virus (HBV) genomes.

Analysis of fatty acids and phytosterols in ethanol extracts of Nelumbo nucifera seeds and rhizomes by GC-MS

The purpose of this study was to investigate the fatty acid and phytosterol contents in ethanol extracts of lotus seeds and rhizomes. These ethanol extracts were extracted with hexane. The hexane extracts were hydrolyzed in a microwave reactor, and total fatty acids and phytosterols were analyzed. The hexane extracts were also subjected to silica gel column chromatography. Nonpolar components (triglycerides and steryl-fatty acid esters) were hydrolyzed, and then the contents were analyzed. Polar components (diglycerides, monoglycerides, fatty acids, and phytosterols) were analyzed directly. Seeds contained higher concentrations of fatty acids and phytosterols compared to rhizomes. Linoleic acid, palmitic acid, and oleic acid were the main fatty acid components in seeds and rhizomes, and most of them in seeds were in the ester form. In seeds, phytosterols existed mainly in the free form rather than in steryl-fatty acid ester form. β-Sitosterol was the most abundant phytosterol in seeds and rhizomes.

[Allelopathic effect of Nelumbo nucifera stem and leaf tissue extract on the growth of Microcystis aeruginosa and Scenedesmus quadricanda]

Effects of Nelumbo nucifera stem and leaf tissue extract on the growth of Microcystis aeruginosa and Scenedesmus quadricanda were studied to verify its potential in entriphication control. Five concentrations of Nelumbo nucifera stem and leaf tissue extract were chosen to compare their inhibitory effects on the growth of Microcystis aeruginosa and Scenedesmus quadricanda. The result showed that the leaf extract inhibited the algae bloom more effectively than the stem extract on the whole. When the leaf extract normality was 25 g x L(-1), the highest inhibition rate of Microcystis aeruginosa and Scenedesmus quadricanda was 71.33% and 78.14%, respectively, while for the stem extract, the values were 49.78% and 52.14%. Propanamide was found in both the stem and leaf tissue extracts of Nelumbo nucifera by GC-MS analysis, with concentrations of 1.1 mg x L(-1) and 0.2 mg x L(-1), respectively. The EC50 values of the two kinds of algae were calculated by the probability method.

Analysis of alkaloids in Lotus (Nelumbo nucifera Gaertn.) leaves by non-aqueous capillary electrophoresis using ultraviolet and mass spectrometric detection

Lotus leaves are a popular remedy in Asia to treat obesity, insomnia and mental impairment; alkaloids are considered most relevant for bioactivity. In this study the first CE method for the determination of all major alkaloids ((-)-nuciferine, (-)-nornuciferine, (-)-caaverine, (-)-armepavine, (+)-norarmepavine, (+)-isoliensinine and (+)-pronuciferine) in Nelumbo nucifera leaves was developed. The optimum buffer showed to be a solution of 100mM ammonium acetate in a mixture of methanol, acetonitrile and water, also containing 0.6% acid acetic. Applied voltage, temperature and detection wavelength were 25kV, 30°C and 225nm; the required analysis time was 15min. By CE-MS all standard compounds could be assigned in positive ESI mode, and two minor alkaloids were tentatively identified (n-nornuciferine and roemerine). A mixture of water, methanol and acetic acid served as sheath liquid in these experiments. The NACE assay was fully validated and utilized to analyze Lotus leaf samples collected in different parts of Vietnam. Respective results revealed significant qualitative and quantitative differences depending on growing area and season. Yet, in all samples (-)-nuciferine (0.34-0.63%), (-)-armepavine (0.13-0.20%), and (+)-isoliensinine (0.06-0.19%) were the most dominant alkaloids. The total alkaloid content varied from 0.72 to 1.41%.

Purified active lotus plumule (Nelumbo nucifera Gaertn) polysaccharides exert anti-inflammatory activity through decreasing toll-like receptor-2 and -4 expressions using mouse primary splenocytes

ETHNOPHARMACOLOGICAL SIGNIFICANCE

Lotus plumule is widely used as traditional Chinese medicine. Among the active components in lotus plumule, polysaccharides exhibit promising potential for its potent anti-inflammatory effects. However, the anti-inflammatory mechanism of purified polysaccharides from lotus plumule remains unknown. To evaluate their anti-inflammatory potential and possible mechanisms of purified polysaccharides in lotus plumule, two active lotus plumule polysaccharides, fractions F1 and F2, were subjected to assay their anti-inflammatory potential and possible mechanisms using murine primary splenocytes in the absence or presence of lipopolysaccharide (LPS).

MATERIALS AND METHODS

Two purified active lotus plumule polysaccharides, F1 and F2, were cultured independently with murine primary splenocytes in the absence or presence of LPS under four different experiment models in vitro. Changes in pro-inflammatory IL-1β, IL-6 and TNF-α, as well as anti-inflammatory IL-10 cytokines secreted by the treated splenocytes were determined using an enzyme-linked immunosorbent assay (ELISA). The amount of toll-like receptor (TLR)-2 and TLR-4 mRNA expression levels in the cells were quantitated using a two-step real-time polymerase chain reaction (PCR) assay.

RESULTS

The results showed that F1 and F2 treatments alone, particularly F2, significantly (P<0.05) decreased pro-/anti-inflammatory (IL-1β/IL-10 and TNF-α/IL-10) cytokine secretion ratios dose-dependently. F1 and F2 treatments in the presence of LPS significantly decreased TLR-2 and/or TLR-4 mRNA expression levels in the splenocytes under inflammatory and repair experiment models.

CONCLUSIONS

The present study proved that F1 and F2 had strong anti-inflammatory effects through inhibiting TLR-2 and/or TLR-4 expressions in the splenocytes in normal, inflammatory and repair situations. Our results further suggest that F2, which is a glycoprotein with low molecular weight of 25.7 kDa, may serve as a promising lead for the development of selective TLR antagonistic agents for inflammatory diseases.

Simultaneous analysis of anthocyanin and non-anthocyanin flavonoid in various tissues of different lotus (Nelumbo) cultivars by HPLC-DAD-ESI-MS(n)

A validated HPLC-DAD-ESI-MS(n) method for the analysis of non-anthocyanin flavonoids was applied to nine different tissues of twelve lotus genotypes of Nelumbo nucifera and N. lutea, together with an optimized anthocyanin extraction and separation protocol for lotus petals. A total of five anthocyanins and twenty non-anthocyanin flavonoids was identified and quantified. Flavonoid contents and compositions varied with cultivar and tissue and were used as a basis to divide tissues into three groups characterized by kaempferol and quercetin derivatives. Influences on flower petal coloration were investigated by principal components analyses. High contents of kaempferol glycosides were detected in the petals of N. nucifera while high quercetin glycoside concentrations occurred in N. lutea. Based on these results, biosynthetic pathways leading to specific compounds in lotus tissues are deduced through metabolomic analysis of different genotypes and tissues and correlations among flavonoid compounds.

[Chemical constituents from leaves of Nelumbo nucifera]

To study the chemical constituents, twenty-seven compounds were isolated from the 70% ethanol extract from leaves of Nelumbo nucifera by modern chromatographic techniques. Their structures were identified as 10-octacosanol (1), beta-sitosterol (2), 1-undecanol (3), 1-eicosanol (4), daucosterol (5), 6'-hydroxy-4,4'-dimethoxychalcone (6), 3,7,8-trimethoxy-1-hydroxy-xanthone (7), rhamnetin-3-O-beta-D-glucopyranoside (8), chrysoeriol-7-O-beta-D-glucoside (9), quercetin-3-O-beta-D-glucopyranoside (10), quercetin-3-O-alpha-L-rhamnopyranosyl (11), hyperoside (12), quercetin-3-O-rutinoside (13), astragalin (14), isorhamnetin-3-O-alpha-L-rhamnopyranosyl-(1--> 6)-[alpha-D-lyxopyranosyl-(1 --> 2) -beta-D-glucopyranoside] (15), isorhamnetin-3-O-alpha-D-lyxopyranosyl-(1 --> 2) -beta-D-glucopyranoside (16), isorhamnetin-3-O-beta-D-glucopyranoside (17), isorhamnetin-3-O-alpha-L-rhamnopyranosyl-(1 --> 6)-beta-D-glucopyranoside (18), quercetin (19), kaempferol (20), dehydronuciferine (21), roemerine (22), stigmast-7-en-3-O-beta-D-glucopyranoside (23), stigmast-7-en-3beta-ol (24), and benzene-1,2-diol (25) on the basis of spectral data analysis. Compounds 1, 6, 7, 8, 24 and 25 were isolated from this plant for the first time, and compounds 15-18 were isolated from the leaves for the first time. Compounds 6, 8, 10, 11, 13 and 15 showed inhibitory activities against beta amyloid (1-42) by A-beta aggregation method with inhibition rates of (63.99 +/- 24.29)%, (79.61 +/- 4.49)%, (49.96 +/- 12.61)%, (101.19 +/- 8.19)%, (88.41+/-6.76)% and (72.48 +/- 8.97)%, respectively.

Green synthesis of silver nanoparticles using Nelumbo nucifera seed extract and its antibacterial activity

Silver nanoparticles (AgNPs) were synthesized using a Nelumbo nucifera dry seed extract, which is a simple, non-toxic, eco-friendly "green material". The synthesized nanoparticles were confirmed by the color changes and characterized by UV-visible spectroscopy. The AgNPs were stable at room temperature for 2 months. Scanning electron microscopy (SEM) revealed the formation of well-dispersed and spherical shapes. Transmission electron microscopy (TEM) of the synthesized AgNPs showed the formation of spherical nanoparticles, 5.03-16.62 nm in size. Fourier transform infrared spectroscopy (FTIR) indicated the involvement of amine, aromatic and alkynes groups in the synthetic process. X-ray diffraction (XRD) confirmed the crystalline nature of AgNPs. These AgNPs were highly toxic to found to Gram negative bacteria.

Alkaloid constituents from flower buds and leaves of sacred lotus (Nelumbo nucifera, Nymphaeaceae) with melanogenesis inhibitory activity in B16 melanoma cells

Methanolic extracts from the flower buds and leaves of sacred lotus (Nelumbo nucifera, Nymphaeaceae) were found to show inhibitory effects on melanogenesis in theophylline-stimulated murine B16 melanoma 4A5 cells. From the methanolic extracts, a new alkaloid, N-methylasimilobine N-oxide, was isolated together with eleven benzylisoquinoline alkaloids. The absolute stereostructure of the new alkaloid was determined from chemical and physicochemical evidence. Among the constituents isolated, nuciferine, N-methylasimilobine, (-)-lirinidine, and 2-hydroxy-1-methoxy-6a,7-dehydroaporphine showed potent inhibition of melanogenesis. Comparison of the inhibitory activities of synthetic related alkaloids facilitated characterization of the structure-activity relationships of aporphine- and benzylisoquinoline-type alkaloids. In addition, 3-30 μM nuciferine and N-methylasimilobine inhibited the expression of tyrosinase mRNA, 3-30 μM N-methylasimilobine inhibited the expression of TRP-1 mRNA, and 10-30 μM nuciferine inhibited the expression of TRP-2 mRNA.

Quantitative determination of phenolic compounds in lotus (Nelumbo nucifera) leaves by capillary zone electrophoresis

The traditional use of lotus leaves as an anti-inflammatory remedy is associated with the occurrence of phenolic compounds. In this study the first CE method for the analysis of all major phenolic constituents in Nelumbo nucifera leaves is presented. It permits the separation of nine relevant markers in less than 10 min. The optimized procedure was fully validated and then used to analyze diverse samples collected in Vietnam. They revealed significant qualitative and quantitative differences depending on growing area and season. Yet, in all of them, quercetin-3-O-β-D-glucuronide, hyperoside, and isoquercitrin were the most dominant flavonoids.

[The application of cation exchange resins in the separation of total flavonoids and alkaloids from seed embryo of Nelumbo nucifera]

OBJECTIVE

To explore the optimal separation condition of the total flavonoids and alkaloids from seed embryo of Nelumbo nucifera.

METHODS

Types of cation exchange resins, concentration of extract liquid, solution volume, velocity of adsorption and eluent were evaluated in separating efficiency with measuring the adsorption ratio and eluent ratio.

RESULTS

D152 resin was finally chosen. After enrichment and purification with it, the purity of flavonoids and alkaloids were significantly increased by 27.08 and 7.86 times, respectively.

CONCLUSION

This method is simple, feasible and suitable for the separation of total flavonoids and alkaloids from seed embryo of Nelumbo nucifera.

Nuciferine stimulates insulin secretion from beta cells-an in vitro comparison with glibenclamide

ETHNOPHARMACOLOGICAL RELEVANCE

Several Asian plants are known for their anti-diabetic properties and produce alkaloids and flavonoids that may stimulate insulin secretion.

MATERIALS AND METHODS

Using Vietnamese plants (Nelumbo nucifera, Gynostemma pentaphyllum, Smilax glabra, and Stemona tuberosa), we extracted two alkaloids (neotuberostemonine, nuciferine) and four flavonoids (astilbin, engeletin, smitilbin, and 3,5,3'-trihydroxy-7,4'-dimethoxyflavone), and studied their insulin stimulatory effects.

RESULTS

Nuciferine, extracted from Nelumbo nucifera, stimulated both phases of insulin secretion in isolated islets, whereas the other compounds had no effect. The effect of nuciferine was totally abolished by diazoxide and nimodipine, and diminished by protein kinase A and protein kinase C inhibition. Nuciferine and potassium had additive effects on insulin secretion. Nuciferine also stimulated insulin secretion in INS-1E cells at both 3.3 and 16.7 mM glucose concentrations. Compared with glibenclamide, nuciferine had a stronger effect on insulin secretion and less beta-cell toxicity. However, nuciferine did not compete with glibenclamide for binding to the sulfonylurea receptor.

CONCLUSIONS

Among several compounds extracted from anti-diabetic plants, nuciferine was found to stimulate insulin secretion by closing potassium-adenosine triphosphate channels, explaining anti-diabetic effects of Nelumbo nucifera.

[Screening of pancreatic lipase and alpha-glucosidase inhibitors from Chinese dietary herbs]

The present study was conducted to develop new inhibitors of pancreatic lipase and alpha-glucosidase from Chinese dietary herbs. Sixty-three dietary herbs from 39 taxonomic families were selected and extracted with aqueous ethanol or water. The extracts were then tested with in vitro enzyme assays for their ability to inhibit pancreatic lipase and alpha-glucosidase activities. Orlistat and acarbose were used as two positive controls. The extracts of Nelumbo nucifera, Curcuma longa, Piper longum and Morus alba showed strong pancreatic lipase inhibitory effects with IC50 at (28.00 +/- 5.51), (5.24 +/- 0.51), (14.76 +/- 2.58), (4.78 +/- 0.58), (3.41 +/- 0.67) mg x L(-1), respectively. These extracts also showed potent alpha-glucosidase inhibitory activities with IC50 at (1.98 +/- 0.13), (0. 18 + 0.007), (0.71 +/- 0.08), (0.077 +/- 0.005), (0.089 +/- 0.006) g x L(-1), respectively. The results provide useful information for developing new drugs or natural health products for hyperlipidemia and hypoglycemia from Chinese dietary herbs.

Antioxidant Activity of Methanol Extract of the Lotus Leaf (Nelumbo nucifera Gertn.)

In this study, hydrogen peroxide ( H 2 O 2)-mediated Caco-2 cytotoxicity was employed to investigate the potential antioxidant activity of the methanol extract from the lotus leaf (Nelumbo nucifera Gertn.). A dose-dependent protective effect against reactive oxygen species (ROS)-induced cytotoxicity was observed when Caco-2 cells were treated with 10 mM H 2 O 2 in combination with the methanol extract of the lotus leaf (0.1–0.3 mg/ml). However, no significant effect was found when co-treating Caco-2 cells with 10 mM H 2 O 2 and α-tocopherol. In vitro assay revealed that the extract exhibited scavenging activities on free radicals and hydroxyl radicals, and metal binding ability as well as reducing power, which may explain in part the mechanism behind the extract's ability to protect cells from oxidative damage. In addition, the extract also exhibited concentration-dependent antioxidant activities against hemoglobin-induced linoleic acid peroxidation and Fenton reaction-mediated plasmid DNA oxidation.

Characterization of oligomeric procyanidins and identification of quercetin glucuronide from lotus ( Nelumbo nucifera Gaertn.) seedpod

Procyanidins are a class of polyphenols in the plant kingdom. Lotus ( Nelumbo nucifera Gaertn.) seedpods, the inedible part of lotus and a byproduct during the production of lotus seeds, were found to be a new source rich in procyanidins. Detailed information about oligomeric procyanidins in lotus seedpods remains unknown. In this study, lotus seedpods were extracted using 60% aqueous methanol and characterized with phloroglucinolysis and liquid chromatography (mass spectrometry with an electrospray ionization source). The results indicate that the oligomeric and polymeric fraction had a mean degree of polymerization of 3.2 and 15.4, respectively, and consisted of (+)-catechin (m/z 289), gallocatechin or epigallocatechin (m/z 305), quercetin glycoside (m/z 463), quercetin glucuronide (m/z 477), procyanidin dimers (m/z 577.1), proanthocyanidin dimer gallate (m/z 593.3), prodelphinidin dimers (m/z 609.1), procyanidin trimers (m/z 865.1), etc. Quercetin glucuronide was further purified using flash chromatography and identified as quercetin-3-O-β-glucuronide by determining its exact mass using ion-trap time-of-flight mass spectrometry and ¹H and ¹³C nuclear magnetic resonance, ¹H-detected heteronuclear single-quantum coherence, and ¹H-detected heteronuclear multiple-bond correlation analyses.

[Separation and purification of flavones from Nelumbo nucifera Gaertn. by silica gel chromatography and high-speed counter-current chromatography]

Three flavones were isolated and purified from Nelumbo nucifera Gaertn. by the combination of silica gel chromatography and high-speed counter-current chromatography (HSCCC). The crude extract of N. nucifera was separated by silica gel chromatography and the fraction containing flavones was obtained. Then, the fraction was separated by HSCCC with two phase solvent systems composed of ethyl acetate-ethanol-water-acetic acid (4: 1 : 5:0.025, v/v/v/v). The upper phase was as the stationary phase and the lower phase as the mobile phase. Under the conditions of a flow rate of 2.0 mL/min, while the apparatus rotated at 800 r/min and the detection wavelength was at 254 nm, 6.1 mg of quercetin-3-O-beta-D-glucuronide, 14.8 mg of myricetin-3-O-beta-D-glucopyranoside and 20. 2 mg of astragalin were obtained from 150 mg of the crude sample in one step. The purities determined by high performance liquid chromatography (HPLC) were 97.0%, 95.4% and 96.3%, respectively. The structures of the target compounds were identified by electrospray ionisation mass spectrometry (ESI-MS), 1H-nuclear magnetic resonance (1H-NMR) and 13C-nuclear magnetic resonance (13C-NMR). This method that has practical value not only saves solvent but also is convenient. It is effective in the separation of flavones from N. nucifera, and provides theoretical foundation for the further development and use of N. nucifera resources.

Perchlorate in soybean sprouts (Glycine max L. Merr.), water dropwort (Oenanthe stolonifera DC.), and lotus (Nelumbo nucifera Gaertn.) root in South Korea

The occurrence of perchlorate in soybean sprouts (Glycine max L. Merr), water dropwort (Oenanthe stolonifera DC.), and lotus (Nelumbo nucifera Gaertn.) root, which are commonly consumed by people in South Korea, was determined by using an ion chromatograph coupled with a tandem mass spectrometer. For soybean sprouts (11 samples), perchlorate was detected in most (91%) of the samples at various concentrations of up to 78.4 μg/kg dry weight (DW); the mean concentration was 35.2 μg/kg DW. For water dropwort, of the 13 samples examined, four showed concentrations that were above the limit of quantification (LOQ). The mean perchlorate concentration was 20.7 μg/kg DW, and the highest perchlorate value was 39.9 μg/kg DW. Of the six lotus root samples examined, only one exhibited a detectable perchlorate concentration (17.3 μg/kg DW). For the accumulation experiments with artificially contaminated solutions, the concentrations of perchlorate in soybean sprouts gradually increased with the increase of perchlorate concentration in the solution. However, there was a decrease in the bioconcentration factor as the perchlorate concentration in the solution increased.

Acute and subchronic oral toxicity studies of Nelumbo nucifera stamens extract in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Since the use of Nelumbo nucifera stamens in herbal medicines as well as in cosmetic products are highly prevalent in Thailand and increasing worldwide, acute and subchronic toxicity studies to confirm the safe use of Nelumbo nucifera stamens are warranted.

AIM OF THE STUDY

Acute and subchronic oral toxicity studies of Nelumbo nucifera stamens extract in rats were performed in the present study in order to evaluate its safety.

MATERIALS AND METHODS

In acute toxicity study, Nelumbo nucifera stamens extract was administered by oral gavage to Sprague-Dawley rats (5 males and 5 females) at a dose of 5000 mg/kg. In subchronic toxicity study, the extract at doses of 50, 100, and 200mg/kg/day were given orally to groups of rats (6 rats/dose/sex) for 90 consecutive days.

RESULTS

The extract at a dose of 5000 mg/kg produced no treatment-related signs of toxicity or mortality in any of the animals tested during 14 days of the study. In the repeated dose 90-day oral toxicity study, there was no significant difference in body weight between the control and all treatment groups with the exception of the body weight of the female group treated with 200mg/kg/day of the extract which was statistically significantly less than that of its control counterpart on day 90 but the percent weight changes of both groups were almost similar. Some statistically significant differences in hematological and biochemical parameters as well as in some internal organ weights of both male and female rats treated with the extract at the highest dose were observed. However, no abnormality of internal organs was observed in both gross and histopathological examinations.

CONCLUSIONS

These results suggest that the oral lethal dose of Nelumbo nucifera stamens extract for male and female rats is in excess of 5000 mg/kg and the no-observed-adverse-effect level (NOAEL) of the extract for both male and female rats is considered to be 200mg/kg/day.

Extract of lotus leaf ( Nelumbo nucifera ) and its active constituent catechin with insulin secretagogue activity

The effect of lotus leaf ( Nelumbo nucifera Gaertn.) on diabetes is unclear. We hypothesized that lotus leaf can regulate insulin secretion and blood glucose levels. The in vitro and in vivo effects of lotus leaf methanolic extract (NNE) on insulin secretion and hyperglycemia were investigated. NNE increased insulin secretion from β cells (HIT-T15) and human islets. NNE enhanced the intracellular calcium levels in β cells. NNE could also enhance phosphorylation of extracellular signal-regulated protein kinases (ERK)1/2 and protein kinase C (PKC), which could be reversed by a PKC inhibitor. The in vivo studies showed that NNE possesses the ability to regulate blood glucose levels in fasted normal mice and high-fat-diet-induced diabetic mice. Furthermore, the in vitro and in vivo effects of the active constituents of NNE, quercetin, and catechin, on glucose-induced insulin secretion and blood glucose regulation were evaluated. Quercetin did not affect insulin secretion, but catechin significantly and dose-dependently enhanced insulin secretion. Orally administered catechin significantly reversed the glucose intolerance in high-fat-diet-induced diabetic mice. These findings suggest that NNE and its active constituent catechin are useful in the control of hyperglycemia in non-insulin-dependent diabetes mellitus through their action as insulin secretagogues.

[Studies of burnt folium nelumbinis in anastalsis and processing]

OBJECTIVE

To research the hemostatic components of burnt Folium Nelumbinis and select a better method of processing.

METHOD

The anastalsis of medicinal materials between various collection period and the main astrictive parts of burnt Folium Nelumbinis were reviewed by slide method. The powder was observed by microscopic identification. The content of alkaloid was assayed by HPLC. The new method of processing was selected by the orthogonal experiment.

RESULT

The lotus leaf in terminal growth can significantly shorten the clotting time and its carbon is more significant which is consistent with other analysis results. The n-butanol part from burnt Folium Nelumbinis can significantly shorten the clotting time. The optimum processing of the new method is 140 degrees C, 20 min and its product meets relevant regulations.

CONCLUSION

In preliminary view, n-butanol part from burnt Folium Nelumbinis is the main astrictive site. It is reasonable to make the lotus leaf in terminal growth into carbon. It is feasible to carbonize by muffle furnace.

Evaluation of hypoglycemic activity of inorganic constituents in Nelumbo nucifera seeds on streptozotocin-induced diabetes in rats

The seeds of Nelumbo nucifera (Lotus) have been used in the traditional system of medicine for various ailments including diabetes. The present study was aimed at analyzing the levels of biologically important trace elements in the lotus seeds by atomic absorption spectroscopy and evaluating the hypoglycemic properties of seed ash on streptozotocin-induced diabetes in rats. Diabetic rats treated with lotus seed ash at a concentration of 200 mg/kg body weight orally for 30 days exhibited significant hypoglycemic activity. The presence of trace elements in appreciable amounts in the seeds may play a direct or indirect role on insulin secretion or its action in a synergetic manner. The hypoglycemic activity of the ash was comparable with glyclazide. The role of trace elements in disorders related to diabetes is also discussed briefly.

Rapid validated HPTLC method for estimation of betulinic acid in Nelumbo nucifera (Nymphaeaceae) rhizome extract

INTRODUCTION

Betulinic acid (pentacyclic triterpenoid) is an important marker component present in Nelumbo nucifera Gaertn. rhizome. N. nucifera rhizome has several medicinal uses including hypoglycaemic, antidiarrhoeal, antimicrobial, diuretic, antipyretic, psychopharmacological activities.

OBJECTIVE

To establish a simple, sensitive, reliable, rapid and validated high-performance thin-layer chromatography method for estimation of betulinic acid in hydro-alcoholic extract of N. nucifera Gaertn. rhizome.

MATERIALS AND METHODS

The separation was carried out on a thin-layer chromatography aluminium plate pre-coated with silica gel 60F(254) , eluted with chloroform, methanol and formic acid (49 : 1 : 1 v/v). Post chromatographic derivatisation was done with anisaldehyde-sulphuric acid reagent and densitometric scanning was performed using a Camag TLC scanner III, at 420 nm.

RESULTS

The system was found to produce a compact spot for betulinic acid (R(f) = 0.30). A good linear precision relationship between the concentrations (2-10 µg) and peak areas were obtained with the correlation coefficient (r) of 0.99698. The limit of detection and limit of quantification of betulinic acid were detected to be 0.4 and 2.30 µg per spot. The percentage of recovery was found to be 98.36%. The percentage relative standard deviations of intra-day and inter-day precisions were 0.82-0.394 and 0.85-0.341, respectively.

CONCLUSION

This validated HPTLC method provides a new and powerful approach to estimate betulinic acid as phytomarker in the extract.